1. Technical Field
The present disclosure relates to a molding material feeding barrel and, particularly, to a molding material feeding barrel for an injection molding apparatus and a molding material feeding system having such molding material feeding barrel.
2. Description of Related Art
Injection molding apparatuses are widely used for manufacturing optical articles, such as light guide plates, lenses, and so on. Generally, an injection molding apparatus includes a molding material feeding system, a melting device, and a mold injection device. Plastic materials are guided to the melting device via the molding material feeding system. The plastic materials are melted and then injected into the injection mold device.
The molding material feeding system typically includes a hopper and a molding material feeding barrel in communication with the hopper. The molding material feeding system is vertically arranged. Molding materials are loaded in the hopper, then flows through the molding material feeding barrel into the melting device. In mass production, the molding material must be loaded in the molding material feeding system time repeatedly to maintain a constant flow of material. The level of the molding material in the molding material feeding barrel should be above a certain level at all times to avoid interruption of the molding materials to the injection mold device.
Typically, a level of the top of the molding materials in the molding material feeding barrel is detected by a sensor installed in the mold feeding barrel. However, static electricity causes material remnants to stick to the inner wall of the mold feeding barrel. As a result the sensor cannot accurately detect the actual material level in the mold feeding barrel. Thus, error conclusions may always be drawn.
Therefore, a molding material feeding barrel and a molding material feeding system using the same which can overcome the above mentioned problems are desired.